f.2Maths=]一元一次不等式

己知一個三角形的任何兩條邊的長度之和必定大於第三條邊的長度,,
=>5+6>x , 5+x>6 and 6+x>5
=>11>x , x>1 and x>-1
=>11>X>1// <---THAT 'S THE FINAL ANSWER!!

let 5+6&gt; x, therefore 11&gt;x (the side with 5cm and the side with 6 cm)

let 5+x&gt;6, therefore x&gt;1

we can not let 6+x&gt;5 (x will be a negative number)

therefore , the answer is 11&gt;x&gt;1

therefore , x can be 2, 3, 4, 5, 6, 7, 8, 9 and 10